I have a collection of old audiobook files that I digitized from magnetic tapes in the early 2000's. Back then storage cost was an issue, and I chose what I thought was the format of the future: mp3PRO and really low bit rate. Is there a decoder available in JRiver for this? It will probably be decoded as a standard mp3, but will sound quite awful.
An alternative solution would be to transcode the files using a player with mp3PRO decoder and e.g. a flac encoder (or whatever format to preserve the information). I have a lifetime license for MusicMatch, but it seems to have disappeared from the surface of the planet, and I do not have an old install file. Any good suggestions?